Both the emergence of multidrug resistant bacteria and the further development and deployment of bioterrorism agents emphasizes the urgency for identifying novel antibiotics. PTC Therapeutics, Inc. is a company dedicated to targeting post-transcriptional cellular pathways by identifying small molecule compounds that bind directly to unique regulatory RNA sequences. Bacterial RNase P is a ubiquitous, structurally conserved RNA-based ribozyme that is essential for maturation of tRNA and thus bacterial cell growth. The enzyme is distinct from its eucaryal counterpart, making it an ideal target for the development of small molecule drugs. There are currently no therapies that target this essential catalytic RNA enzyme. The applicants have developed a high throughput FP assay that is robust, reproducible and has been validated against a 3,400 compound library. The investigators propose to screen the PTC's extensive small molecule compound library for inhibitors of Escherichia coli RNase P. Inhibitors of the E. coli enzyme (type A) will be tested against enzymes obtained from Staphylococcus aureus and Bacillus subtilis (both of the type B class). Bacteria predominantly contain either type A or B RNase P, and compounds shown to inhibit both types of enzymes will be characterized by their ability to inhibit growth of vancomycin resistant Enterococci and multidrug resistant Staphylococcus aureus (MRSA). Broad-spectrum inhibitors will be further tested for inhibition of the eucaryal RNase P enzyme and cytotoxicity against a panel of mammalian cell lines.